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Subject[PATCH 10/12] perf, x86: Support LBR filtering by INTX/NOTX/ABORT v3
Date
From: Andi Kleen <ak@linux.intel.com>

Add LBR filtering for branch in transaction, branch not in transaction
or transaction abort. This is exposed as new sample types.

v2: Rename ABORT to ABORTTX
v3: Use table instead of if
Signed-off-by: Andi Kleen <ak@linux.intel.com>
---
arch/x86/kernel/cpu/perf_event_intel_lbr.c | 58 ++++++++++++++++++++++------
include/uapi/linux/perf_event.h | 5 ++-
2 files changed, 50 insertions(+), 13 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event_intel_lbr.c b/arch/x86/kernel/cpu/perf_event_intel_lbr.c
index ad5af13..0be69fd 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_lbr.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_lbr.c
@@ -16,6 +16,14 @@ enum {
LBR_FORMAT_MAX_KNOWN = LBR_FORMAT_EIP_FLAGS2,
};

+static enum {
+ LBR_EIP_FLAGS = 1,
+ LBR_TSX = 2,
+} lbr_desc[LBR_FORMAT_MAX_KNOWN + 1] = {
+ [LBR_FORMAT_EIP_FLAGS] = LBR_EIP_FLAGS,
+ [LBR_FORMAT_EIP_FLAGS2] = LBR_EIP_FLAGS | LBR_TSX,
+};
+
/*
* Intel LBR_SELECT bits
* Intel Vol3a, April 2011, Section 16.7 Table 16-10
@@ -85,9 +93,13 @@ enum {
X86_BR_JMP = 1 << 9, /* jump */
X86_BR_IRQ = 1 << 10,/* hw interrupt or trap or fault */
X86_BR_IND_CALL = 1 << 11,/* indirect calls */
+ X86_BR_ABORT = 1 << 12,/* transaction abort */
+ X86_BR_INTX = 1 << 13,/* in transaction */
+ X86_BR_NOTX = 1 << 14,/* not in transaction */
};

#define X86_BR_PLM (X86_BR_USER | X86_BR_KERNEL)
+#define X86_BR_ANYTX (X86_BR_NOTX | X86_BR_INTX)

#define X86_BR_ANY \
(X86_BR_CALL |\
@@ -99,6 +111,7 @@ enum {
X86_BR_JCC |\
X86_BR_JMP |\
X86_BR_IRQ |\
+ X86_BR_ABORT |\
X86_BR_IND_CALL)

#define X86_BR_ALL (X86_BR_PLM | X86_BR_ANY)
@@ -275,22 +288,23 @@ static void intel_pmu_lbr_read_64(struct cpu_hw_events *cpuc)
for (i = 0; i < x86_pmu.lbr_nr; i++) {
unsigned long lbr_idx = (tos - i) & mask;
u64 from, to, mis = 0, pred = 0, intx = 0, abort = 0;
+ int skip = 0;
+ int lbr_flags = lbr_desc[lbr_format];

rdmsrl(x86_pmu.lbr_from + lbr_idx, from);
rdmsrl(x86_pmu.lbr_to + lbr_idx, to);

- if (lbr_format == LBR_FORMAT_EIP_FLAGS ||
- lbr_format == LBR_FORMAT_EIP_FLAGS2) {
+ if (lbr_flags & LBR_EIP_FLAGS) {
mis = !!(from & LBR_FROM_FLAG_MISPRED);
pred = !mis;
- if (lbr_format == LBR_FORMAT_EIP_FLAGS)
- from = (u64)((((s64)from) << 1) >> 1);
- else if (lbr_format == LBR_FORMAT_EIP_FLAGS2) {
- intx = !!(from & LBR_FROM_FLAG_INTX);
- abort = !!(from & LBR_FROM_FLAG_ABORT);
- from = (u64)((((s64)from) << 3) >> 3);
- }
+ skip = 1;
+ }
+ if (lbr_flags & LBR_TSX) {
+ intx = !!(from & LBR_FROM_FLAG_INTX);
+ abort = !!(from & LBR_FROM_FLAG_ABORT);
+ skip = 3;
}
+ from = (u64)((((s64)from) << skip) >> skip);

cpuc->lbr_entries[i].from = from;
cpuc->lbr_entries[i].to = to;
@@ -347,6 +361,16 @@ static void intel_pmu_setup_sw_lbr_filter(struct perf_event *event)

if (br_type & PERF_SAMPLE_BRANCH_IND_CALL)
mask |= X86_BR_IND_CALL;
+
+ if (br_type & PERF_SAMPLE_BRANCH_ABORTTX)
+ mask |= X86_BR_ABORT;
+
+ if (br_type & PERF_SAMPLE_BRANCH_INTX)
+ mask |= X86_BR_INTX;
+
+ if (br_type & PERF_SAMPLE_BRANCH_NOTX)
+ mask |= X86_BR_NOTX;
+
/*
* stash actual user request into reg, it may
* be used by fixup code for some CPU
@@ -393,7 +417,8 @@ int intel_pmu_setup_lbr_filter(struct perf_event *event)
/*
* no LBR on this PMU
*/
- if (!x86_pmu.lbr_nr || x86_pmu.intel_cap.lbr_format > LBR_FORMAT_MAX_KNOWN)
+ if (!x86_pmu.lbr_nr ||
+ x86_pmu.intel_cap.lbr_format > LBR_FORMAT_MAX_KNOWN)
return -EOPNOTSUPP;

/*
@@ -421,7 +446,7 @@ int intel_pmu_setup_lbr_filter(struct perf_event *event)
* decoded (e.g., text page not present), then X86_BR_NONE is
* returned.
*/
-static int branch_type(unsigned long from, unsigned long to)
+static int branch_type(unsigned long from, unsigned long to, int abort)
{
struct insn insn;
void *addr;
@@ -441,6 +466,9 @@ static int branch_type(unsigned long from, unsigned long to)
if (from == 0 || to == 0)
return X86_BR_NONE;

+ if (abort)
+ return X86_BR_ABORT | to_plm;
+
if (from_plm == X86_BR_USER) {
/*
* can happen if measuring at the user level only
@@ -577,7 +605,13 @@ intel_pmu_lbr_filter(struct cpu_hw_events *cpuc)
from = cpuc->lbr_entries[i].from;
to = cpuc->lbr_entries[i].to;

- type = branch_type(from, to);
+ type = branch_type(from, to, cpuc->lbr_entries[i].abort);
+ if (type != X86_BR_NONE && (br_sel & X86_BR_ANYTX)) {
+ if (cpuc->lbr_entries[i].intx)
+ type |= X86_BR_INTX;
+ else
+ type |= X86_BR_NOTX;
+ }

/* if type does not correspond, then discard */
if (type == X86_BR_NONE || (br_sel & type) != type) {
diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h
index 9fa9c62..41b25f0 100644
--- a/include/uapi/linux/perf_event.h
+++ b/include/uapi/linux/perf_event.h
@@ -155,8 +155,11 @@ enum perf_branch_sample_type {
PERF_SAMPLE_BRANCH_ANY_CALL = 1U << 4, /* any call branch */
PERF_SAMPLE_BRANCH_ANY_RETURN = 1U << 5, /* any return branch */
PERF_SAMPLE_BRANCH_IND_CALL = 1U << 6, /* indirect calls */
+ PERF_SAMPLE_BRANCH_ABORTTX = 1U << 7, /* transaction aborts */
+ PERF_SAMPLE_BRANCH_INTX = 1U << 8, /* in transaction (flag) */
+ PERF_SAMPLE_BRANCH_NOTX = 1U << 9, /* not in transaction (flag) */

- PERF_SAMPLE_BRANCH_MAX = 1U << 7, /* non-ABI */
+ PERF_SAMPLE_BRANCH_MAX = 1U << 10, /* non-ABI */
};

#define PERF_SAMPLE_BRANCH_PLM_ALL \
--
1.7.7.6


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